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How does the ACSC calculate capacity in realtime?

Resolution:
There are two methods used by the ACSC to calculate the unit performance.

In Spot-Discrete mode the unit measures the refrigerant suction and discharge pressures to calculate the compressor performance; then subtracts the losses from fan and compressor heat and the condensate production to arrive at the unit net sensible cooling capacity. This method is more accurate, and hence preferred, however cannot be used in modes when the HGB valve is active.

In all other modes the unit measures the condenser entering and leaving air temperatures and condenser fan speed to calculate total heat rejection; then subtracts the losses from fan and compressor heat, compressor power consumption and condensate production to arrive at the unit net sensible cooling capacity. This method must be used because the HGB valve is operating in theses modes.